title: Efficacy of two commercially available, low-magnesium, urine-acidifying dry foods for the dissolution of struvite uroliths in cats.
abstract: OBJECTIVE
  To compare the efficacy and safety of using 2 commercially available, low-magnesium, urine-acidifying dry foods to dissolve sterile struvite uroliths in cats.
  
  
  METHODS
  Prospective, multicenter, randomized clinical trial .
  
  
  METHODS
  37 cats with presumed struvite uroliths.
  
  
  METHODS
  Cats were randomly assigned to be fed 1 of 2 low-magnesium, urine-acidifying dry foods (food A or B). For each cat, physical examination, urinalysis, and abdominal radiography were performed weekly to assess treatment response.
  
  
  RESULTS
  32 cats had complete urolith dissolution. Mean ± SD times for a 50% reduction in urolith size (0.69 ± 0.1 weeks) and complete urolith dissolution (13.0 ± 2.6 days) were significantly shorter for cats fed food A, compared with those (1.75 ± 0.27 weeks and 27.0 ± 2.6 days, respectively) for cats fed food B. At study termination, mean ± SD urine pH (6.083 ± 0.105) for cats fed food A was lower than that (6.431 ± 0.109) for cats fed food B. In 5 cats, uroliths did not dissolve and were subsequently determined to be composed of 100% ammonium urate (n = 4) or 100% calcium oxalate (1). Adverse events associated with diet were not observed in any of the cats.
  
  
  CONCLUSIONS
  Results indicated that dietary dissolution is safe and effective for eradication of sterile struvite uroliths in cats. Cats fed food A had faster urolith dissolution than did cats fed food B. Lack of a reduction in urolith size at 2 weeks after diet initiation was indicative of misdiagnosis or noncompliance.
authors.affiliation: Minnesota Urolith Center, Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55105.
authors.forename: Jody P
authors.initials: JP
authors.lastname: Lulich
authors.forename: John M
authors.initials: JM
authors.lastname: Kruger
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Macleay
authors.forename: Jane M
authors.initials: JM
authors.lastname: Merrills
authors.forename: Inke
authors.initials: I
authors.lastname: Paetau-Robinson
authors.forename: Hasan
authors.initials: H
authors.lastname: Albasan
authors.forename: Carl A
authors.initials: CA
authors.lastname: Osborne
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002371:Cat Diseases / Q000178:diet therapy*; D002415:Cats; D004032:Diet / Q000662:veterinary*; D005260:Female; D017616:Magnesium Compounds / Q000737:chemistry* / Q000652:urine; D008297:Male; D010710:Phosphates / Q000737:chemistry* / Q000652:urine; D000069877:Struvite; D052878:Urolithiasis / Q000178:diet therapy / Q000662:veterinary*
chemical_list: D017616:Magnesium Compounds; D010710:Phosphates; D000069877:Struvite